Hi guys and gals,

I've done a bit of searching on this site and have seen the threads about faulty fuel pressure regulators, but wanted to post anyway for some opinions. I have a 2007 S40 T5 that over the last 6 months has developed a problem. It started happening only now and then, but now pretty much happens 9 out of 10 times I attempt to start it COLD.

This is the sequence of events:

1. Insert key and crank as normal. I get ignition early but then the RPM won't get over IDLE, and it just dies. What I do with the gas pedal makes no difference. Fly by wire.

2. Second attempt starts perfectly and jumps up to 1500rpm (cold).

3. Subsequent starts while still warm are normal.

I have attached a video. Volume is a little low unfortunately.


PS. I have NFI how the scratches on the instrument screen happened. Bought the car like that.

Thanks all!

 

to the forum SirRedNob

 

Thanks

 

The 2007 does not have a fuel pressure regulator like the 2000-2004 models with the 1.9L engine. The newer 2004.5 and up models use a fuel pressure sensor. This is because fuel pressure is controlled by varying the voltage to the fuel pump.

So first thing I would do is check the fuel pressure in the morning when it's cold. There should be some pressure holding in the fuel rail. Zero pressure means a faulty check valve in the pump. After the engine is shut off the pressure should not go to zero.

 

Thanks Hudini!

Do I need any special tools to test fuel pressure? Easy to do?

 

there's a schraeder valve on the end of the fuel rail (like a tire's valve) - you can hook the pressure gauge to that - and then position the gauge such that you can see it from the driver's seat to watch as you sequence through your start process. Check to see if your local parts store has tool rentals. (some of the big box stores do...)

 

Harbor Freight has a cheap tester for $20. It's called a fuel injection pump tester for some reason.

Fuel Pressure Tester & Fuel Injection Pump Tester

 

I've had similar issues on my 03 S40 with 70k miles. I didn't want any expensive repairs, so I changed the fuel filter. Didn't completely solve the issue but made it infinitely better. The fuel that came out of the old filter was black.